1. Technical Field
The present invention relates to a method of forming a bonded body and a bonded body, and more particularly, a method of forming a bonded body and the bonded body formed by the method.
2. Related Art
Conventionally, when two members (base members) are bonded together to obtain a bonded body, an adhesive such as an epoxy-based adhesive, an urethane-based adhesive, or a silicone-based adhesive has been often used.
In general, an adhesive exhibits reliably high adhesiveness regardless of constituent materials of the members to be bonded. Therefore, members constituted of various materials can be bonded together in various combinations.
For example, in a case where such a bonded body is used in a droplet ejection head (an ink-jet type recording head) included in an ink-jet printer, the droplet ejection head is assembled by bonding, using an adhesive, several members constituted of different kinds of materials such as a resin-based material, a metal-based material, and a silicon-based material.
When the members are to be bonded together using the adhesive to obtain an assembled body composed from the members, a liquid or paste adhesive is applied to surfaces of the members, and then the members are attached to each other via the adhesive applied on the surfaces thereof and firmly fixed together by hardening (setting) the adhesive with an action of heat or light.
However, in the case where the members are bonded together using the adhesive, there are problems in that bonding strength between the members is low, dimensional accuracy of the obtained assembled body is low, and it takes a relatively long time until the adhesive is hardened.
Further, it is often necessary to treat the surfaces of the members to be bonded using a primer in order to improve the bonding strength between the members. Therefore, additional cost and labor hour are required for performing the primer treatment, which causes an increase in cost and complexity of the process for bonding the members.
On the other hand, there is known a solid bonding method as a method of forming a bonded body without using the adhesive. The solid bonding method is a method of directly bonding members without an intervention of an intermediate layer constituted of an adhesive or the like (see, for example, JP-A-5-82404).
Since such a solid bonding method does not need to use the intermediate layer constituted of the adhesive or the like for bonding the members, it is possible to obtain a bonded body having high dimensional accuracy.
However, in the case where the members are bonded together using the solid bonding method, there are problems in that constituent materials of the members to be bonded are limited to specific kinds, a heat treatment must be carried out at a high temperature (e.g., about 700 to 800° C.) in a bonding process, and an atmosphere in the bonding process is limited to a reduced atmosphere.
In view of such problems, there is a demand for a method which is capable of firmly bonding members with high dimensional accuracy and efficiently bonding them at a low temperature regardless of constituent materials of the members to be bonded.